Pictures of Meningitis

Meningitis is the inflammation of the protective membranes covering the central nervous system, known collectively as the meninges. It may develop due to a variety of causes, including infective agents, physical injury, cancer, or certain drugs. Meningitis is a serious condition owing to the proximity of the location to the brain and spinal cord. The potential for serious damage to motor control, thought processes, or even death, warrants prompt medical attention.

Causes
Most cases of meningitis are caused by microorganisms, such as viruses, bacteria, fungi, or parasites, that spread into the blood and into the cerebrospinal fluid (CSF). Non-infectious causes include cancers, systemic lupus erythematosus and certain drugs. Although the most common cause of meningitis is viral, bacterial, or Meningococcal meningitis -- the second most frequent cause -- can be serious and life-threatening. Anyone suspected of having meningitis should have prompt medical evaluation.

Epidemiology
Age group Causes
Neonates Group B Streptococci, Escherichia coli, Listeria monocytogenes
Infants Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae
Children N. meningitidis, S. pneumoniae
Adults S. pneumoniae, N. meningitidis, Mycobacteria, Cryptococci
Meningitis can affect anyone in any age group, from the newborn to the elderly.

The African Meningitis Belt
The "Meningitis Belt" is an area in sub-Saharan Africa which stretches from Senegal in the west to Ethiopia in the east in which large epidemics of meningococcal meningitis occur (this largely coincides with the Sahel region). It contains an estimated total population of 300 million people. The largest epidemic outbreak was in 1996, when over 250,000 cases occurred and 25,000 people died as a consequence of the disease.

Clinical symptoms
Meningitis usually presents with one or more of the following symptoms.

High fever, sometimes with chills
Severe headache
Nausea or vomiting
Light sensitivity (photophobia)
Sound sensitivity
Neurological signs such as drowsiness or confusion
Twitching
Sleepiness
Opisthotonus
Irritability
Sore throat
Delirium (particularly in children)
Seizures (occurs in about 20 to 40 percent of patients).
Nuchal rigidity (stiff neck, occurs in less than 50 percent of cases, but if seen, it is considered pathognomonic).
Swelling of fontanelle (soft spot) in infants.
One large prospective study demonstrated that the classic triad of nuchal rigidity, fever, and mental status change was present in only 44 percent of confirmed cases of community acquired bacterial meningitis. Headache was the most common reported symptom (87 percent) followed by neck stiffness (83 percent).

Nuchal rigidity is typically assessed with the patient lying supine, and both hips and knees flexed. If pain is elicited when the knees are passively extended (Kernig's sign), this indicates nuchal rigidity and meningitis. In infants, forward flexion of the neck may cause involuntary knee and hip flexion (Brudzinski's sign). Although commonly tested, the sensitivity and specificity of Kernig's and Brudzinski's tests are uncertain.
Neck stiffness may prevent the head from bending forwards. If the child can touch the chest with the chin by bending the head forwards the physical sign of neck stiffness is probably not present. Neck stiffness in a child with a fever is a medical emergency.

In "meningococcal" meningitis (i.e. meningitis caused by the bacteria Neisseria meningitidis), a rapidly-spreading petechial rash is typical, and may precede other symptoms. The rash consists of numerous small, irregular purple or red spots on the trunk, lower extremities, mucous membranes, conjunctiva, and occasionally on the palms of hands and soles of feet.

Symptoms in infants under 12 months include high fever, fretfulness, irritability - particularly when handled, difficulty awakening, drowsiness, difficulty feeding, and/or a stiff neck, or bulging fontanelle (soft spot on top of head).

In a recent validation study published in the Journal of the American Medical Association (JAMA), a Bacterial Meningitis Score in children over the age of 2 months with at least 1 risk factor (positive CSF Gram Stain, CSF absolute neutrophil count ≥ 1000 cell/µL, CSF protein ≥ 80 mg/dL, peripheral blood absolute neutrophil count ≥ 10,000 cell/µL, history of seizure before or at presentation time) has a sensitivity of 100% (95% CI, 96.9%-100%), specificity of 63.5% (95% CI, 61.4%-65.6%), and negative predictive value of 100% (95% CI, 99.8%-100%) in predicting bacterial meningitis based on data collected from 20 academic medical centers as part of the Pediatric Emergency Medicine Collaborative Research Committee of the American Academy of Pediatrics.

Diagnosis

Laboratory tests
If meningitis is suspected based on clinical examination, the patient should be given antibiotics. The next step is to perform laboratory tests on the blood and cerebrospinal fluid (CSF).

CSF is obtained by means of a lumbar puncture (LP). However, if the patient is at risk for elevated intracranial pressure, a lumbar puncture may be contraindicated because of the possibility of fatal brain herniation. In such cases a CT or MRI scan should be performed prior to the lumbar puncture in order to make sure there are no large masses compressing the brain. Patients at risk for elevated intracranial pressure include those with recent head trauma, the immunocompromised, those with a known CNS neoplasm, or focal neurologic deficits such as papilledema or altered consciousness. Otherwise, the CT or MRI should be performed after the LP, with MRI preferred over CT due to its superiority in demonstrating areas of cerebral edema, ischemia, and meningeal inflammation.

The opening pressure is noted during the LP and the CSF sent for examination of white blood cell, red blood cell, glucose, and protein, and may have different tests performed, such as gram staining, culture, and possibly latex agglutination test, limulus lysates, or polymerase chain reaction (PCR) for bacterial or viral DNA. If the patient is immunocompromised, the doctor may also consider testing the CSF for toxoplasmosis, Epstein-Barr virus, cytomegalovirus, JC virus and fungal infection.

CSF analysis in bacterial meningitis

An autopsy demonstrating signs of pneumococcal meningitis. The forceps (center) are retracting the dura mater (white). Underneath the dura mater are the leptomeninges, which are edematous and have multiple small hemorrhagic foci (red).Opening pressure: > 180 mm H2O
White Blood Cells: 10-10,000/uL with neutrophil predominance
Glucose: < 40 mg/dL
CSF glucose to serum glucose ratio: < 0.4
Protein: > 4.5 mg/dL
Gram stain: positive in >60%
Culture: positive in >80%
Latex agglutination: may be positive in meningitis due to Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Escherichia coli, Group B Streptococci
Limulus lysates: positive in Gram-negative meningitis
Cultures are often negative if CSF is taken after the administration of antibiotics. In these patients, PCR can be helpful in arriving at a diagnosis. It has been suggested that CSF cortisol measurement may be helpful.

CSF analysis in viral meningitis
Appearance is clear
Will contain lymphocytes (lymphocytosis)
Normal level of protein
Normal or increased level of glucose

Treatment

Bacterial meningitis

Bacterial meningitis is a medical emergency and has a high mortality rate if untreated. All suspected cases, however mild, need emergency medical attention. Empiric antibiotics must be started immediately, even before the results of the lumbar puncture and CSF analysis are known. Antibiotics started within 4 hours of lumbar puncture will not significantly affect lab results.

The choice of antibiotic depends on local advice. In most of the developed world, the most common organisms involved are Streptococcus pneumoniae and Neisseria meningitidis: first line treatment in the UK is a third-generation cephalosporin (such as ceftriaxone or cefotaxime). In those under 3 years of age, over 50 years of age, or immunocompromised, ampicillin should be added to cover Listeria monocytogenes. In the U.S. and other countries with high levels of penicillin resistance, the first line choice of antibiotics is vancomycin and a carbapenem (such as meropenem). In sub-Saharan Africa, oily chloramphenicol or ceftriaxone are often used because only a single dose is needed in most cases.

Staphylococci and gram-negative bacilli are common infective agents in patients who have just had a neurosurgical procedure. Again, the choice of antibiotic depends on local patterns of infection: cefotaxime and ceftriaxone remain good choices in many situations, but ceftazidime is used when Pseudomonas aeruginosa is a problem, and intraventricular vancomycin is used for those patients with intraventricular shunts because of high rates of staphylococcal infection. In patients with intracerebral prosthetic material (metal plates, electrodes or implants, etc.) then sometimes chloramphenicol is the only antibiotic that will adequately cover infection by Staphylococcus aureus (cephalosporins and carbapenems are inadequate under these circumstances).

Once the results of the CSF analysis are known along with the Gram-stain and culture, empiric therapy may be switched to therapy targeted to the specific causative organisms. Because antibiotic-resistance is a prevalent problem, information from drug susceptibility testing should also be gathered.

Neisseria meningitidis (Meningococcus) can usually be treated with a 7-day course of IV antibiotics:
Penicillin-sensitive -- penicillin G or ampicillin
Penicillin-resistant -- ceftriaxone or cefotaxime
Prophylaxis for close contacts (contact with oral secretions) -- rifampin 600 mg bid for 2 days (adults) or 10 mg/kg bid (children). Rifampin is not recommended in pregnancy and as such, these patients should be treated with single doses of ciprofloxacin, azithromycin, or ceftriaxone
Streptococcus pneumoniae (Pneumococcus) can usually be treated with a 2-week course of IV antibiotics:
Penicillin-sensitive -- penicillin G
Penicillin-intermediate -- ceftriaxone or cefotaxime
Penicillin-resistant -- ceftriaxone or cefotaxime + vancomycin
Listeria monocytogenes is treated with a 3-week course of IV ampicillin + gentamicin.
Gram negative bacilli -- ceftriaxone or cefotaxime
Pseudomonas aeruginosa -- ceftazidime
Staphylococcus aureus
Methicillin-sensitive -- nafcillin
Methicillin-resistant -- vancomycin
Streptococcus agalactiae -- penicillin G or ampicillin
Haemophilus influenzae -- ceftriaxone or cefotaxime

Viral meningitis
Unlike bacteria, viruses cannot be killed by antibiotics. Patients with very mild viral meningitis may only have to spend a few hours in a hospital, while those who have a more serious infection may be hospitalised for many more days for supportive care. Patients with mild cases, which often cause only flu-like symptoms, may be treated with fluids, bed rest (preferably in a quiet, dark room), and analgesics for pain and fever. Serious cases, especially in the case of young children or neonates, may require the use of antiviral drugs, such as acyclovir. The physician may also prescribe anticonvulsants such as phenytoin to prevent seizures and corticosteroids to reduce brain inflammation. If inflammation is severe, pain medicine and sedatives may be prescribed to make the patient more comfortable.

Fungal meningitis
This form of meningitis is rare in healthy people, but is a higher risk in those who have AIDS. Antifungals to combat the infection are usually administered, as well as fluids and medicine to control pain and fever. Often the pathogen in these cases is Cryptococcus Sp.

Complications
There are several potential disabilities resulting from damage to the nervous system. These include seizures (with its concommitant brain damage), sensorineural hearing loss, hydrocephalus, and cerebral palsy.

A common complication is loss of hearing as a result from damages to the hair cells in the cochlea, making them unable to transmit fluid-borne sound vibrations into electrical signaling to the auditory cortex. Hearing may be restored with the use of a cochlear implant, with better prognosis for the patient if they receive it early. As time passes from the meningitis until the implantation, the liquid in the cochlea may become progressively stiffer, first like jelly and then already within two months it may become hard like bone, making the implantation impossible to perform. But if the implant is received quickly enough, the resulting artificial hearing may be very good. A one-year-old child completely losing all hearing and receiving implants within 4 weeks can get an artificial hearing that is good enough to understand spoken language as well as, or even better than average children of the same age.

Vaccination
All current vaccines target only bacterial meningitis.

Vaccinations against Haemophilus influenzae (Hib) have decreased early childhood meningitis significantly.

Vaccines against type A and C Neisseria meningitidis, the kind that causes most disease in preschool children and teenagers in the United States, have also been around for a while. Type A is also prevalent in sub-Sahara Africa and W135 outbreaks have affected those on the Hajj pilgrimage to Mecca.

A vaccine called MeNZB for a specific strain of type B Neisseria meningitidis prevalent in New Zealand has completed trials and is being given to many people in the country under the age of 20. There is also a vaccine, MenBVac, for the specific strain of type B meningoccocal disease prevalent in Norway, and another specific vaccine for the strain prevalent in Cuba.

Pneumovax (also known as Prevenar) against Streptococcus pneumoniae is recommended for all people 65 years of age or older, and for all newborns starting at 6 weeks - 2 months, according to American Association of Pediatrics (AAP) recommendations.

History
Meningitis may have been described in the Middle Ages, but it was first accurately identified by the Swiss Vieusseux (a scientific-literary association) during an outbreak in Geneva, Switzerland in 1805.

In the 19th century, meningitis was a scourge of the Japanese imperial family, playing the largest role in the horrendous pre-maturity death rate the family endured. In the mid-1800s, only the Emperor Kōmei and two of his siblings reached maturity out of fifteen total children surviving birth. Kōmei's son, the Emperor Meiji, was one of two survivors out of Kōmei's six children, including an elder brother of Meiji who would have taken the throne had he lived to maturity. Five of Meiji's 15 children survived, including only his third son, Emperor Taishō, who was feeble-minded, perhaps as a result of having contracted meningitis himself. By Emperor Hirohito's generation the family was receiving modern medical attention. As the focal point of tradition in Japan, during the Tokugawa Shogunate the family was denied modern "Dutch" medical treatment then in use among the upper caste; despite extensive modernization during the Meiji Restoration the Emperor insisted on traditional medical care for his children.

Pictures of Meningitis

Lipoflavanoid

Lipoflavonoid is a proprietary, over-the-counter, nutrient formula created in 1961, by DSE Healthcare Solutions, to help combat tinnitus (ringing in the ears), although it has not been approved by the Food and Drug Administration. It was shown to improve blood circulation in the inner ear canal. At least one medical study [1] concluded that Lipoflavonoid provides a beneficial effect for patients suffering from tinnitus due to Meniere's disease. The manufacturer does not claim that Lipoflavonoid provides beneficial effects for tinnitus due to other causes. Lipoflavonoid is a registered trademark.

Ingredients
Three capsule dose:

Active
Vitamin C (ascorbic acid) 300 mg 500% daily value (DV)
Vitamin B-1 (thiamin mononitrate) 1 mg 67% DV
Vitamin B-2 (riboflavin) 1 mg 59% DV
Niacin (niacinamide) 10 mg 50% DV
Vitamin B6 (pyridoxine HCl) 1 mg 50% DV
Vitamin B-12 (Cyanocobalamin) 5 µg 83% DV
Pantothenic acid (calcium pantothenate) 5 mg 50% DV
Choline (choline bitartrate) 334 mg DV(unk)
Bioflavonoids (lemon bioflavonoids complex) 300 mg DV(unk)
Inositol 334 mg

Inactive
disbasic calcium phosphate
microcrystalline cellulose
croscamellose sodium
stearic acid
hydroxypropyl methylcellulose
magnesium stearate
pharmaceutical glaze
polyethylene glycol
titanium dioxide
ethyl vanillin
FD&C yellow #6 (Sunset Yellow FCF)
FD&C red #40 lake
FD&C blue #1 lake.
Contains no sugar, starch, yeast, wheat, maize, milk products, or preservatives.

Notice: As with all medications, please consult with a medical professional, especially if pregnant or nursing a baby, before taking this product.

Lipoflavanoid

Hepatic Cyst MRI Results

Hepatocellular carcinoma (HCC, also called hepatoma) is a primary malignancy (cancer) of the liver. Most cases of HCC are secondary to either a viral hepatitide infection (hepatitis B or C) or cirrhosis (alcoholism being the most common cause of hepatic cirrhosis). In countries where hepatitis is not endemic, most malignant cancers in the liver are not primary HCC but metastasis (spread) of cancer from elsewhere in the body, e.g. the colon. Treatment options of HCC and prognosis are dependent on many factors but especially on tumor size and staging.

Outside of the West, the usual outcome is poor, because only 10 - 20% of hepatocellular carcinomas can be removed completely using surgery. If the cancer cannot be completely removed, the disease is usually deadly within 3 to 6 months. This is partially due to late presentation with large tumours, but also the lack of medical expertise and facilities. This is a rare tumor in the United States.

Epidemiology
HCC is the 5th most common tumor worldwide. The epidemiology of HCC exhibits two main patterns, one in North America and Western Europe and another in non-Western countries, such as those in sub-Saharan Africa, central and Southeast Asia, and the Amazon basin. Males are affected more than females usually and it is more common between the 3rd and 5th decades of life Hepatocellular carcinoma causes 662,000 deaths worldwide per year.

Non-Western Countries
In some parts of the world—such as sub-Saharan Africa and Southeast Asia—HCC is the most common cancer, generally affecting men more than women, and with an age of onset between late teens and 30s. This variability is in part due to the different patterns of hepatitis B transmission in different populations - infection at or around birth predispose to earlier cancers than if people are infected later. The time between hepatitis B infection and development into HCC can be years even decades, but from diagnosis of HCC to death the average survival period is only 5.9 months, according to one Chinese study during the 1970-80s, or 3 months (median survival time) in Sub-Saharan Africa according to Manson's textbook of tropical diseases. HCC is one of the deadliest cancers in China. Food infected with Aspergillus flavus (especially peanuts and corns stored during prolonged wet seasons) which produces aflatoxin, poses another risk factor for HCC.

North America and Western Europe
Most malignant tumors of the liver discovered in Western patients are metastases (spread) from tumors elsewhere. In the West, HCC is generally seen as rare cancer, normally of those with pre-existing liver disease. It is often detected by ultrasound screening, and so can be discovered by health-care facilities much earlier than in developing regions such as Sub-Saharan Africa.

Acute and chronic hepatic porphyrias (acute intermittent porphyria, porphyria cutanea tarda, hereditary coproporphyria, variegate porphyria) and tyrosinemia type I are risk factors for hepatocellular carcinoma. The diagnosis of an acute hepatic porphyria (AIP, HCP, VP) should be sought in patients with hepatocellular carcinoma without typical risk factors of hepatitis B or C, alcoholic liver cirrhosis or hemochromatosis. Both active and latent genetic carriers of acute hepatic porphyrias are at risk for this cancer, although latent genetic carriers have developed the cancer at a later age than those with classic symptoms. Patients with acute hepatic porphyrias should be monitored for hepatocellular carcinoma.

Pathogenesis
Hepatocellular carcinoma like any other cancer, develops when there is a mutation to the cellular machinery that causes the cell to replicate at a higher rate and/or results in the cell avoiding apoptosis. In particular, chronic infections of Hepatitis B and/or C can aid the development of hepatocellular carcinoma by repeatedly causing the body's own immune system to attack the liver cells, some of which are infected by the virus, others merely bystanders. This constant cycle of damage, followed by repair can lead to mistakes during repair which in turn lead to carcinogenesis. Alternatively, repeated consumption of large amounts ethanol can have a similar effect. The toxin aflatoxin from certain Aspergillus species of fungus is a carcinogen and aids carcinogenesis of hepatocellular cancer by building up in the liver. The combined high prevalence of rates of aflaxtoxin and hepatitis B in countries like China and western Africa has led to relatively high rates of heptatocellular carcinoma in these regions. Other viral hepatitides such as hepatitis A have no potential to become a chronic infection and thus are not related to hepatocellular carcinoma.

Diagnosis, screening and monitoring
Hepatocellular carcinoma (HCC) most commonly appears in a patient with chronic viral hepatitis (hepatitis B or hepatitis C, 20%) or with cirrhosis (about 80%). These patients commonly undergo surveillance with ultrasound due to the cost-effectiveness.

In patients with a higher suspicion of HCC (such as rising alpha-fetoprotein and des-gamma carboxyprothrombin levels), the best method of diagnosis involves a CT scan of the abdomen using intravenous contrast agent and three-phase scanning (before contrast administration, immediately after contrast administration, and again after a delay) to increase the ability of the radiologist to detect small or subtle tumors. It is important to optimize the parameters of the CT examination, because the underlying liver disease that most HCC patients have can make the findings more difficult to appreciate.

On CT, HCC can have three distinct patterns of growth:

A single large tumor
Multiple tumors
Poorly defined tumor with an infiltrative growth pattern
The key characteristics on CT are hypervascularity in the arterial phase scans, washout or de-enhancement in the portal and delayed phase studies, a pseudocapsule and a mosaic pattern. Both calcifications and intralesional fat may be appreciated.

In patients who have a contrast agent allergy or poor renal function, an MRI scan of the abdomen is a more costly but effective substitute.

Once imaged, diagnosis is confirmed by percutaneous biopsy and histopathologic analysis.

Pathology
Macroscopically, liver cancer appears as a nodular or infiltrative tumor. The nodular type may be solitary (large mass) or multiple (when developed as a complication of cirrhosis). Tumor nodules are round to oval, grey or green (if the tumor produces bile), well circumscribed but not encapsulated. The diffuse type is poorly circumscribed and infiltrates the portal veins, or the hepatic veins (rarely).

Microscopically, there are four architectural and cytological types (patterns) of hepatocellular carcinoma: fibrolamellar, pseudoglandular (adenoid), pleomorphic (giant cell) and clear cell. In well differentiated forms, tumor cells resemble hepatocytes, form trabeculae, cords and nests, and may contain bile pigment in cytoplasm. In poorly differentiated forms, malignant epithelial cells are discohesive, pleomorphic, anaplastic, giant. The tumor has a scant stroma and central necrosis because of the poor vascularization.1

Staging and prognosis
Important features that guide treatment include: -

size
spread (stage)
involvement of liver vessels
presence of a tumor capsule
presence of extrahepatic metastases
presence of daughter nodules
vascularity of the tumor
MRI is the best imaging method to detect the presence of a tumor capsule.

Treatment
Liver transplantation to replace the liver with a cadaver liver or a live donor lobe. Historically low survival rates (20%-36%) recent improvement (61.1%; 1996-2001), likely related to adoption of Milan criteria at US transplantation centers. If the tumor disease has metastasized, the immuno-suppressant post-transplant drugs decrease the chance of survival. NIH
Surgical resection to remove a tumor to treat small or slow-growing tumors if they are diagnosed early. This treatment offers the best prognosis for long-term survival but unfortunately is possible in only 10-15% of cases. Resection in cirrhotic patients carries high morbidity and mortality. Medicinenet
Percutaneous ethanol injection (PEI) well tolerated, high RR in small (< 3 cm) solitary tumors; as of 2005, no randomized trial comparing resection to percutaneous treatments; recurrence rates similar to those for postresection.
Transcatheter arterial chemoembolization (TACE) is usually perform in the treatment of large tumors (larger than 3 cm and less than 4 cm in diameter) most frequently performed by intraarterially injecting an infusion of antineoplastic agents mixed with iodized oil (such as Lipiodol). As of 2005, multiple trials show objective tumor responses and slowed tumor progression but questionable survival benefit compared to supportive care; greatest benefit seen in patients with preserved liver function, absence of vascular invasion, and smallest tumors.
Radiofrequency ablation (RFA) uses high frequency radio-waves to ablate the tumour.
Intra-arterial iodine-131–lipiodol administration Efficacy demonstrated in unresectable patients, those with portal vein thrombus. This treatment is also used as adjuvant therapy in resected patients (Lau at et, 1999). It is believed to raise the 3-year survival rate from 46 to 86%. This adjuvant therapy is in phase III clinical trials in Singapore and is available as a standard medical treatment to qualified patients in Hong Kong.
Combined PEI and TACE can be used for tumors larger than 4 cm in diameter, although some Italian groups have had success with larger tumours using TACE alone.
High intensity focused ultrasound (HIFU) (not to be confused with normal diagnostic ultrasound) is a new technique which uses much more powerful ultrasound to treat the tumour. Still at a very experimental stage. Most of the work has been done in China. Some early work is being done in Oxford and London in the UK.
Hormonal therapy Antiestrogen therapy with tamoxifen studied in several trials, mixed results across studies, but generally considered ineffective Octreotide (somatostatin analogue) showed 13-month MS v 4-month MS in untreated patients in a small randomized study; results not reproduced.
Chemotherapy adjuvant: No randomized trials showing benefit of neoadjuvant or adjuvant systemic therapy in HCC; single trial showed decrease in new tumors in patients receiving oral synthetic retinoid for 12 months after resection/ablation; results not reproduced. Clinical trials have varying results.
Palliative: Regimens that included doxorubicin, cisplatin, fluorouracil, interferon, epirubicin, or taxol, as single agents or in combination, have not shown any survival benefit (RR, 0%-25%); a few isolated major responses allowed patients to undergo partial hepatectomy; no published results from any randomized trial of systemic chemotherapy.
Cryosurgery: Cryosurgery is a new technique that can destroy tumors in a variety of sites (brain, breast, kidney, prostate, liver). Cryosurgery is the destruction of abnormal tissue using sub-zero temperatures. The tumor is not removed and the destroyed cancer is left to be reabsorbed by the body. Initial results in properly selected patients with unresectable liver tumors are equivalent to those of resection. Cryosurgery involves the placement of a stainless steel probe into the center of the tumor. Liquid nitrogen is circulated through the end of this device. The tumor and a half inch margin of normal liver are frozen to -190°C for 15 minutes, which is lethal to all tissues. The area is thawed for 10 minutes and then re-frozen to -190°C for another 15 minutes. After the tumor has thawed, the probe is removed, bleeding is controlled, and the procedure is complete. The patient will spend the first post-operative night in the intensive care unit and typically is discharged in 3 - 5 days. Proper selection of patients and attention to detail in performing the cryosurgical procedure are mandatory in order to achieve good results and outcomes. Frequently, cryosurgery is used in conjunction with liver resection as some of the tumors are removed while others are treated with cryosurgery. Patients may also have insertion of a hepatic intra-arterial artery catheter for post-operative chemotherapy. As with liver resection, your surgeon should have experience with cryosurgical techniques in order to provide the best treatment possible.
Interventional radiology
Abbreviations: HCC, hepatocellular carcinoma; TACE, transarterial embolization/chemoembolization; PFS, progression-free survival; PS, performance status; HBV, hepatitis B virus; PEI, percutaneous ethanol injection; RR, response rate; MS, median survival.

Awareness
The Jade Ribbon Campaign is used for awareness of liver cancer in the Pacific Islands and will be introduced into America someday.

Jade is the official color of liver cancer.

Future directions
Current research includes the search for the genes that are disregulated in HCC, protein markers, and other predictive biomarkers. As similar research is yielding results in various other malignant diseases, it is hoped that identifying the aberrant genes and the resultant proteins could lead to the identification of pharmacological interventions for HCC.

Hepatic Cyst MRI Results

Surgical Foreskin Replacement

Foreskin restoration is the process of expanding the residual skin on the penis, via surgical or non-surgical methods, to create the appearance of a natural foreskin (prepuce) covering the glans penis. Foreskin restoration techniques are most commonly undertaken by men who have been circumcised or who have sustained an injury, but are also used by uncircumcised men who desire a longer foreskin and by men who have phimosis.

Reasons for foreskin restoration
Men attempt foreskin restoration for many reasons. These may range from simply wanting their foreskin back, to restoring a natural appearance, desire for improved sensitivity of the glans or better sexual stimulation, and regaining a sense of wholeness. Some men cite a desire to regain a sense of control over their sexual organs and regaining lost self esteem. Foreskin restoration may also be seen as a form of body modification for those interested.

History
In classical Greek times the exposure of the glans of the penis was considered offensive and men with short foreskin would wear the Kynodesme to prevent its accidental exposure.

A form of foreskin restoration, historically known as epispasm, was practiced among some Jews in Hellenistic and Roman societies.

European Jews, along with men circumcised for medical reasons, sought out underground foreskin restoration operations during World War II as a method to escape Nazi persecution.

The practice was revived in the late twentieth century using modern materials and techniques. In 1982 a group called Brothers United for Future Foreskins (BUFF) was formed, which publicized the use of tape in non-surgical restoration methods. Later in 1991, another group called UNCircumcising Information and Resources Centers (UNCIRC) was formed.

The National Organization of Restoring Men (NORM) was founded in 1989 in San Francisco, as a non-profit support group for men restoring their foreskins. It was originally known as RECAP, an acronym for the phrase Recover A Penis. In 1994 UNCIRC was incorporated into this group. Since its founding, several NORM chapters have been founded throughout the United States, as well as internationally in Canada, the United Kingdom, Australia, New Zealand, and Germany.

Surgical techniques
Surgical methods of foreskin restoration, sometimes known as foreskin reconstruction, usually involve a method of grafting skin onto the distal portion of the penile shaft. The grafted skin is typically taken from the scrotum, which contains the same smooth muscle (known as dartos fascia) as does the skin of the penis. One method involves a four stage procedure in which the penile shaft is buried in the scrotum for a period of time. Such techniques are costly, and have the potential to produce unsatisfactory results or serious complications related to the skin graft.

British Columbian resident Paul Tinari, who was forcibly circumcised at the age of nine, has spoken with news media about his experience. Following a lawsuit Tinari's surgical foreskin restoration was covered by the British Columbia Ministry of Health. The plastic surgeon who performed the restoration was the first in Canada to have done such an operation, and used a technique similar to that described above.

Nonsurgical techniques
Nonsurgical foreskin restoration, accomplished through tissue expansion, is the more commonly used method of foreskin restoration. Both the skin of the penile shaft and the mucosal inner lining of the foreskin, if any remains after circumcision, may be expanded.

The skin is pulled forward over the glans, and tension is applied manually, by using weights, or by using elastic straps. In the second two cases a device must be attached to the skin; surgical tape is often used. An example of a device using elastic straps is the T-Tape method, which was developed in the 1990s with the idea of enabling restoration to take place more rapidly. Many specialized foreskin restoration devices that grip the skin with or without tape are also commercially available. Tension from these devices may be applied by weights or elastic straps, by pushing the skin forward on the penis, or by a combination of these methods.

The amount of tension produced by any method must be adjusted to avoid causing injury, pain or discomfort, and may be seen as a limiting factor in foreskin restoration. There is a risk of damaging tissues from the use of excessive tension or applying tension for too long. Websites about foreskin restoration vary in their recommendations, from suggesting a regimen of moderate amounts of tension applied for several hours a day, to recommending periods of higher tension applied for only a few minutes per day.

Tissue stretching has long been known to stimulate mitosis, and research shows that regenerated human tissues have the attributes of the original tissue. Unlike conventional skin expansion techniques, however, the process of nonsurgical foreskin restoration may take several years to complete, and depends on the amount of skin available to expand, the amount of skin desired in the end, and the regimen of stretching methods used. Patience and dedication are needed; support groups exist to help with these. The act of stretching the skin is often described informally as "tugging" in these groups, especially those on the internet.

Results
Results of surgical foreskin restoration are much faster, but are often described as unsatisfactory, and most restoration groups advise against them.

Results of non-surgical methods vary widely, and depend on such factors as the amount of skin present at the start of the restoration, degree of commitment, technique, and the individual's body. Foreskin restoration only creates the appearance of a natural foreskin; certain parts of the natural foreskin cannot be reformed. In particular, the frenar band, a muscle sheath that helps to contract the tip of the foreskin so that it remains positioned over the glans, requires minor plastic surgery to recreate. Restored foreskins often appear much looser at the tip and some men report difficulty in keeping the glans covered. This can be alleviated by creating increased length, but requires a longer commitment to the restoration program. In addition, several websites claim that the use of O-rings during the restoration program can train the skin to maintain a puckered shape.

Physical aspects
The natural foreskin has three principal components, in addition to blood vessels, nerves and connective tissue: skin, which is exposed exteriorly; mucous membrane, which is the surface in contact with the glans penis when the penis is flaccid; and a band of muscle within the tip of the foreskin. Generally, the skin grows more readily in response to stretching than does the mucous membrane. The ring of muscle which normally holds the foreskin closed is often completely removed in the majority of circumcisions and cannot be regrown, so the covering achieved via stretching techniques is usually looser than that of a natural foreskin. According to some observers, however, it is difficult to distinguish a restored foreskin from a natural foreskin because restoration produces a "nearly normal-appearing prepuce."

Nonsurgical foreskin restoration does not restore portions of the frenulum or the ridged band removed during circumcision. Although not commonly performed, there are surgical "touch-up" techniques that can re-create some of the functionality of the frenulum and dartos muscle.

The process of foreskin restoration seeks to regenerate some of the tissue removed by circumcision, as well as providing coverage of the glans. According to research, the foreskin comprises over half of the skin and mucosa of the human penis,

In some men, foreskin restoration may alleviate certain problems they attribute to their circumcisions. Such problems, as reported to an anti-circumcision group by men circumcised in infancy or childhood, include prominent scarring (33%), insufficient penile skin for comfortable erection (27%), erectile curvature from uneven skin loss (16%), and pain and bleeding upon erection/manipulation (17%). The poll also asked about awareness of or involvement in foreskin restoration, and included an open comment section. Many respondents and their wives "reported that restoration resolved the unnatural dryness of the circumcised penis, which caused abrasion, pain or bleeding during intercourse, and that restoration offered unique pleasures, which enhanced sexual intimacy."

Foreskin restoration can be a means for man (and his sexual partner) to experience the rolling and gliding action of the penile shaft skin along the erect shaft. This mode of stimulation is not available to circumcised men without restoration.

Some men who have undertaken foreskin restoration report a visibly smoother glans, which they attribute to decreased levels of keratinization following restoration. However, a study that investigated the effect of glans coverage on levels of keratinisation found no difference in keratin levels within the group studied.

Although research studies have found no measurable difference with respect to glans sensitivity, some men have reported a qualitative improvement in sensitivity of the glans. Some have suggested that the perceived sensitivity gains of the glans are psychological, with glans sensitivity itself being unaffected. According to some, however, protecting the glans from dryness and abrasion with clothing can allow the glans texture to change to a quality similar to that of intact genitalia among men who undergo this process.


Emotional, psychological, and psychiatric aspects
Foreskin restoration has been reported as having beneficial emotional results in some men, and has been proposed as a treatment for negative feelings in some adult men about their infant circumcisions. Such claims are not supported by all medical authorities, however.

Such negative feelings were discussed in the poll mentioned above. Respondents suffered from: emotional distress, manifesting as intrusive thoughts about one's circumcision, including feelings of mutilation (60%), low self-esteem/inferiority to intact men (50%), genital dysmorphia (55%), rage (52%), resentment/depression (59%), violation (46%), or parental betrayal (30%). Many respondents (41%) reported that their physical/emotional suffering impeded emotional intimacy with partner(s), resulting in sexual dysfunction. Almost a third of respondents (29%) reported dependence on substances or behaviors to relieve their suffering (tobacco, alcohol, drugs, food and/or sexual compulsivity).

In "Prepuce Restoration Seekers: Psychiatric Aspects," a 1981 report published in the Archives of Sexual Behavior, four men seeking surgical foreskin restoration were examined. The report provides descriptions of the motivational forces behind the desire for foreskin restoration among these four men.

Surgical Foreskin Replacement

Hirschsprung's Diseaes

All diseases that pertain to the gastrointestinal tract are labelled as digestive diseases. This includes diseases of the esophagus, stomach, first, second and third part of the duodenum, jejunum, ileum, the ileo-cecal complex, large intestine (ascending, transverse and descending colon) sigmoid colon and rectum.

The gastrointestinal tract (GI tract), also called the digestive tract, or the alimentary canal, is the system of organs within multicellular animals that takes in food, digests it to extract energy and nutrients, and expels the remaining waste. The major functions of the GI tract are digestion and excretion.

The GI tract differs substantially from animal to animal. For instance, some animals have multi-chambered stomachs, while some animals' stomachs contain a single chamber. In a normal human adult male, the GI tract is approximately 6.5 meters (20 feet) long and consists of the upper and lower GI tracts. The tract may also be divided into foregut, midgut, and hindgut, reflecting the embryological origin of each segment of the tract.

Upper gastrointestinal tract
The upper GI tract consists of the mouth, pharynx, esophagus, and stomach.

The mouth contains the buccal mucosa, which contains the openings of the salivary glands; the tongue; and the teeth.
Behind the mouth lies the pharynx, which leads to a hollow muscular tube, the esophagus.
Peristalsis takes place, which is the contraction of muscles to propel the food down the esophagus which extends through the chest and pierces the diaphragm to reach the stomach.
The stomach, in turn, leads to the small intestine.
The upper GI tract roughly corresponds to the derivatives of the foregut, with the exception of the first part of the duodenum (see below for more details.)

Lower gastrointestinal tract
The lower GI tract comprises the intestines and anus.

Bowel or intestine
small intestine, which has three parts:
duodenum
jejunum
ileum
large intestine, which has three parts:
cecum (the vermiform appendix is attached to the cecum).
colon (ascending colon, transverse colon, descending colon and sigmoid flexure)
rectum
anus

Accessory organs
Accessory organs to the alimentary canal include the liver, gallbladder, and pancreas. The liver secretes bile into the small intestine via the biliary system, employing the gallbladder as a reservoir. Apart from storing and concentrating bile, the gallbladder has no other specific function. The pancreas secretes an isosmotic fluid containing bicarbonate and several enzymes, including trypsin, chymotrypsin, lipase, and pancreatic amylase, as well as nucleolytic enzymes (deoxyribonuclease and ribonuclease), into the small intestine. Both of these secretory organs aid in digestion.

Embryology
The gut is an endoderm-derived structure. At approximately the 16th day of human development, the embryo begins to fold ventrally (with the embryo's ventral surface becoming concave) in two directions: the sides of the embryo fold in on each other and the head and tail fold towards one another. The result is that a piece of the yolk sac, an endoderm-lined structure in contact with the ventral aspect of the embryo, begins to be pinched off to become the primitive gut. The yolk sac remains connected to the gut tube via the vitelline duct. Usually this structure regresses during development; in cases where it does not, it is known as Meckel's diverticulum.

During fetal life, the primitive gut can be divided into three segments: foregut, midgut, and hindgut. Although these terms are often used in reference to segments of the primitive gut, they are nevertheless used regularly to describe components of the definitive gut as well.

Each segment of the primitive gut gives rise to specific gut and gut-related structures in the adult. Components derived from the gut proper, including the stomach and colon, develop as swellings or dilatations of the primitive gut. In contrast, gut-related derivatives—that is, those structures that derive from the primitive gut but are not part of the gut proper—in general develop as outpouchings of the primitive gut. The blood vessels supplying these structures remain constant throughout development.

Part Range in adult Gives rise to Arterial supply
foregut the pharynx, to the upper duodenum pharynx, esophagus, stomach, upper duodenum, respiratory tract (including the lungs), liver, gallbladder, and pancreas branches of the celiac artery
midgut lower duodenum, to the first half of the transverse colon lower duodenum, jejunum, ileum, cecum, appendix, ascending colon, and first half of the transverse colon branches of the superior mesenteric artery
hindgut second half of the transverse colon, to the upper part of the anal canal remaining half of the transverse colon, descending colon, rectum, and upper part of the anal canal branches of the inferior mesenteric artery


Physiology

Specialization of organs
Four organs are subject to specialization in the kingdom Animalia.

The first organ is the tongue which is only present in the phylum Chordata.
The second organ is the esophagus. The crop is an enlargement of the esophagus in birds, insects and other invertebrates that is used to store food temporarily.
The third organ is the stomach. In addition to a glandular stomach (proventriculus), birds have a muscular "stomach" called the ventriculus or "gizzard." The gizzard is used to mechanically grind up food.
The fourth organ is the large intestine. An outpouching of the large intestine called the cecum is present in non-ruminant herbivores such as rabbits. It aids in digestion of plant material such as cellulose

Immune function
The gastrointestinal tract is also a prominent part of the immune system.[2] The low pH (ranging from 1 to 4) of the stomach is fatal for many microorganisms that enter it. Similarly, mucus (containing IgA antibodies) neutralizes many of these microorganisms. Other factors in the GI tract help with immune function as well, including enzymes in the saliva and bile. Enzymes such as Cyp3A4, along with the antiporter activities, are also instrumental in the intestine's role of detoxification of antigens and xenobiotics, such as drugs, involved in first pass metabolism. Health-enhancing intestinal bacteria serve to prevent the overgrowth of potentially harmful bacteria in the gut. Microorganisms are also kept at bay by an extensive immune system comprising the gut-associated lymphoid tissue (GALT).


Histology
The GI tract has a uniform general histology with some differences which reflect the specialization in functional anatomy.[3] The GI tract can be divided into 4 concentric layers:

mucosa
submucosa
muscularis externa (the external muscle layer)
adventitia or serosa

Mucosa
The mucosa is the innermost layer of the GI tract, surrounding the lumen, or space within the tube. This layer comes in direct contact with the food (or bolus), and is responsible for absorption and secretion, important processes in digestion.

The mucosa can be divided into:

epithelium
lamina propria
muscularis mucosae
The mucosae are highly specialized in each organ of the GI tract, facing a low pH in the stomach, absorbing a multitude of different substances in the small intestine, and also absorbing specific quantities of water in the large intestine. Reflecting the varying needs of these organs, the structure of the mucosa can consist of invaginations of secretory glands (eg, gastric pits), or it can be folded in order to increase surface area (examples include villi and plicae circulares).


Submucosa
The submucosa consists of a dense irregular layer of connective tissue with large blood vessels, lymphatics and nerves branching into the mucosa and muscularis. It contains Meissner's plexus, an enteric nervous plexus, situated on the inner surface of the muscularis externa.


Muscularis externa
The muscularis externa consists of a circular inner muscular layer and a longitudinal outer muscular layer. The circular muscle layer prevents the food from going backwards and the longitudinal layer shortens the tract. The coordinated contractions of these layers is called peristalsis and propels the bolus, or balled-up food, through the GI tract. Between the two muscle layers are the myenteric or Auerbach's plexus.


Adventitia/Serosa
The adventitia consists of several layers of epithelia. When the adventitia is facing the mesentery or peritoneal fold, the adventitia is covered by a mesothelium supported by a thin connective tissue layer, together forming a serosa, or serous membrane.


Human uses of animal gut
The use of animal gut strings by musicians can be traced back to the third dynasty of Egypt. In the recent past, strings were made out of lamb gut. With the advent of the modern era, musicians have tended to use strings made of silk, or synthetic materials such as nylon or steel. Some instrumentalists, however, still use gut strings in order to evoke the older tone quality. Although such strings were commonly referred to as "catgut" strings, cats were never used as a source for gut strings.
Sheep gut was the original source for natural gut string used in racquets, such as for tennis. Today, synthetic strings are much more common, but the best strings are now made out of cow gut.
Gut cord has also been used to produce strings for the snares which provide the snare drum's characteristic buzzing timbre. While the snare drum currently almost always uses metal wire rather than gut cord, the North African bendir frame drum still uses gut for this purpose.
"Natural" sausage hulls (or casings) are made of animal gut, especially hog, beef, and lamb.
Animal gut was used to make the cord lines in longcase clocks and for fusee movements in bracket clocks, but may be replaced by metal wire.
The oldest condoms found were made from animal intestine.

Hirschsprung's Diseaes

Is Colour Blindness Dominant or Recessive Desease

Color blindness, (also known as Dyschromatopsia) or color vision deficiency, in humans is the inability to perceive differences between some or all colors that other people can distinguish. It is most often of genetic nature, but may also occur because of eye, nerve, or brain damage, or due to exposure to certain chemicals. The English chemist John Dalton in 1798 published the first scientific paper on the subject, "Extraordinary facts relating to the vision of colours", after the realization of his own color blindness; because of Dalton's work, the condition is sometimes called Daltonism, although this term is now used for a type of color blindness called deuteranopia.

Color blindness is usually classed as disability; however, in selected situations color blind people may have advantages over people with normal color vision. There are some studies which conclude that color blind individuals are better at penetrating certain camouflages. Monochromats may have a minor advantage in dark vision, but only in the first five minutes of dark adaptation.

Background
Main article: Trichromatic color vision
The normal human retina contains two kinds of light sensitive cells: the rod cells (active in low light) and the cone cells (active in normal daylight). Normally, there are three kinds of cones, each containing a different pigment. The cones are activated when the pigments absorb light. The absorption spectra of the pigments differ; one is maximally sensitive to short wavelengths, one to medium wavelengths, and the third to long wavelengths (their peak sensitivities are in the blue, yellowish-green, and yellow regions of the spectrum, respectively). The absorption spectra of all three systems cover much of the visible spectrum, so it is not entirely accurate to refer to them as "blue", "green" and "red" receptors, especially because the "red" receptor actually has its peak sensitivity in the yellow. The sensitivity of normal color vision actually depends on the overlap between the absorption spectra of the three systems: different colors are recognized when the different types of cone are stimulated to different extents. Red light, for example, stimulates the long wavelength cones much more than either of the others, and reducing wavelength causes the other two cone systems to be increasingly stimulated as well, causing a gradual change in hue.

Causes
There are many types of color blindness. The most common are red-green hereditary (genetic) photoreceptor disorders, but it is also possible to acquire color blindness through damage to the retina, optic nerve, or higher brain areas. Higher brain areas implicated in color processing include the parvocellular pathway of the lateral geniculate nucleus of the thalamus, and visual area V4 of the visual cortex. Acquired color blindness is generally unlike the more typical genetic disorders. For example, it is possible to acquire color blindness only in a portion of the visual field but maintain normal color vision elsewhere. Some forms of acquired color blindness are reversible. Transient color blindness also occurs (very rarely) in the aura of some migraine sufferers.

The different kinds of inherited color blindness result from partial or complete loss of function of one or more of the different cone systems. When one cone system is compromised, dichromacy results. The most frequent forms of human color blindness result from problems with either the middle or long wavelength sensitive cone systems, and involve difficulties in discriminating reds, yellows, and greens from one another. They are collectively referred to as "red-green color blindness", though the term is an over-simplification and somewhat misleading. Other forms of color blindness are much more rare. They include problems in discriminating blues from yellows, and the rarest forms of all, complete color blindness or monochromacy, where one cannot distinguish any color from grey, as in a black-and-white movie or photograph.

Classification of color deficiencies

By etiology

The colors of the rainbow as viewed by a person with no color vision deficiencies.
The colors of the rainbow as viewed by a person with protanopia.
The colors of the rainbow as viewed by a person with deuteranopia.
The colors of the rainbow as viewed by a person with tritanopia.Color vision deficiencies can be classified as acquired or inherited/congenital.
Acquired
Inherited/congenital. There are three types of inherited or congenital color vision deficiencies: monochromacy, dichromacy, and anomalous trichromacy.
Monochromacy, also known as "total color blindness", is the lack of ability to distinguish colors; caused by cone defect or absence. Monochromacy occurs when two or all three of the cone pigments are missing and color and lightness vision is reduced to one dimension.
Rod monochromacy (achromatopsia) is a rare, nonprogressive inability to distinguish any colors as a result of absent or nonfunctioning retinal cones. It is associated with light sensitivity (photophobia), involuntary eye oscillations (nystagmus), and poor vision.
Cone monochromacy is a rare, total color blindness that is accompanied by relatively normal vision, electoretinogram, and electrooculogram.
Dichromacy is a moderately severe color vision defect in which one of the three basic color mechanisms is absent or not functioning. It is hereditary and sex-linked, affecting predominantly males. ] Dichromacy occurs when one of the cone pigments is missing and color is reduced to two dimensions.
Protanopia is a severe type of color vision deficiency caused by the complete absence of red retinal photoreceptors. It is a form of dichromatism in which red appears dark. It is congenital, sex-linked, and present in 1% of all males.
Deuteranopia is a color vision deficiency in which the green retinal photoreceptors are absent, moderately affecting red-green hue discrimination. It is a form of dichromatism in which there are only two cone pigments present. It is likewise hereditary, sex-linked, and present in 1% of all males.
Tritanopia is an exceedingly rare color vision disturbance in which there are only two cone pigments present and a total absence of blue retinal receptors.
Anomalous trichromacy is a common type of congenital color vision deficiency, occuring when one of the three cone pigments is altered in its spectral sensitivity. This results in an impairment, rather than loss, of trichromacy (normal three-dimensional color vision).
Protanomaly is a mild color vision defect in which an altered spectral sensitivity of red retinal receptors (closer to green receptor response) results in poor red-green hue discrimination. It is congenital, sex-linked, and present in 1% of all males. It is often passed from mother to child.
Deuteranomaly, caused by a similar shift in the green retinal receptors, is the most common type of color vision deficiency, mildly affecting red-green hue discrimination in 5% of all males. It is hereditary and sex-linked.
Tritanomaly is a rare, hereditary color vision deficiency affecting blue-yellow hue discrimination.

By clinical appearance
Based on clinical appearance, color blindness may be described as total or partial. Total color blindness is much less common than partial color blindness. There are two major types of color blindness: those who have difficulty distinguishing between red and green, and those who have difficulty distinguishing between blue and yellow.
Total color blindness
Partial color blindness
Red-green
Dichromacy (protanopia and deuteranopia)
Anomalous trichromacy (protanomaly and deuteranomaly)
Blue-yellow
Dichromacy (tritanopia)
Anomalous trichromacy (tritanomaly)

Congenital color vision deficiencies
Congenital color vision deficiencies are subdivided based on the number of primary hues needed to match a given sample in the visible spectrum.

Monochromacy
Monochromacy is the condition of possessing only a single channel for conveying information about color. Monochromats possess a complete inability to distinguish any colors and perceive only variations in brightness. It occurs in two primary forms:

Rod monochromacy, frequently called achromatopsia, where the retina contains no cone cells, so that in addition to the absence of color discrimination, vision in lights of normal intensity is difficult. While normally rare, achromatopsia is very common on the island of Pingelap, a part of the Pohnpei state, Federated States of Micronesia, where it is called maskun: about 1/12 of the population there has it. The island was devastated by a storm in the 18th century, and one of the few male survivors carried a gene for achromatopsia; the population is now several thousand, of whom about 30% carry this gene.
Cone monochromacy is the condition of having both rods and cones, but only a single kind of cone. A cone monochromat can have good pattern vision at normal daylight levels, but will not be able to distinguish hues. Blue cone monochromacy (X chromosome) is caused by a complete absence of L- and M-cones. It is encoded at the same place as red-green color blindness on the X chromosome. Peak spectral sensitivities are in the blue region of the visible spectrum (near 440 nm). They generally show nystagmus ("jiggling eyes"), photophobia (light sensitivity), reduced visual acuity, and myopia (nearsightedness). Visual acuity usually falls to the 20/50 to 20/400 range

Dichromacy
Protanopes, deuteranopes, and tritanopes are dichromats; that is, they can match any color they see with some mixture of just two spectral lights (whereas normally humans are trichromats and require three lights). These individuals normally know they have a color vision problem and it can affect their lives on a daily basis. Protanopes and deuteranopes see no perceptible difference between red, orange, yellow, and green. All these colors that seem so different to the normal viewer appear to be the same color for this two percent of the population.

This image shows the number 37, but someone who is protanopic may not be able to see it.Protanopia (1% of males): Lacking the long-wavelength sensitive retinal cones, those with this condition are unable to distinguish between colors in the green-yellow-red section of the spectrum. They have a neutral point at a wavelength of 492 nm—that is, they cannot discriminate light of this wavelength from white. For the protanope, the brightness of red, orange, and yellow is much reduced compared to normal. This dimming can be so pronounced that reds may be confused with black or dark gray, and red traffic lights may appear to be extinguished. They may learn to distinguish reds from yellows and from greens primarily on the basis of their apparent brightness or lightness, not on any perceptible hue difference. Violet, lavender, and purple are indistinguishable from various shades of blue because their reddish components are so dimmed as to be invisible. E.g. Pink flowers, reflecting both red light and blue light, may appear just blue to the protanope. Very few people have been found who have one normal eye and one protanopic eye. These unilateral dichromats report that with only their protanopic eye open, they see wavelengths below the neutral point as blue and those above it as yellow. This is a rare form of color blindness.

This image shows the number 49, but someone who is deuteranopic may not be able to see it.Deuteranopia (1% of males): Lacking the medium-wavelength cones, those affected are again unable to distinguish between colors in the green-yellow-red section of the spectrum. Their neutral point is at a slightly longer wavelength, 498 nm. The deuteranope suffers the same hue discrimination problems as the protanope, but without the abnormal dimming. The names red, orange, yellow, and green really mean very little to him aside from being different names that every one else around him seems to be able to agree on. Similarly, violet, lavender, purple, and blue, seem to be too many names to use logically for hues that all look alike to him. This is one of the rarer forms of colorblindness making up about 1% of the male population, also known as Daltonism after John Dalton. (Dalton's diagnosis was confirmed as deuteranopia in 1995, some 150 years after his death, by DNA analysis of his preserved eyeball.) Deuteranopic unilateral dichromats report that with only their deuteranopic eye open, they see wavelengths below the neutral point as blue and those above it as yellow.

This image shows the number 56, but someone who is tritanopic may not be able to see it.Tritanopia (less than 1% of males): Lacking the short-wavelength cones, those affected are unable to distinguish between the colors in the blue-yellow section of the spectrum.

Anomalous trichromacy
Those with protanomaly, deuteranomaly, or tritanomaly are trichromats, but the color matches they make differ from the normal. They are called anomalous trichromats. In order to match a given spectral yellow light, protanomalous observers need more red light in a red/green mixture than a normal observer, and deuteranomalous observers need more green. From a practical stand point though, many protanomalous and deuteranomalous people breeze through life with very little difficulty doing tasks that require normal color vision. Some may not even be aware that their color perception is in any way different from normal. The only problem they have is passing a color vision test.

Protanomaly and deuteranomaly can be readily observed using an instrument called an anomaloscope, which mixes spectral red and green lights in variable proportions, for comparison with a fixed spectral yellow. If this is done in front of a large audience of men, as the proportion of red is increased from a low value, first a small proportion of people will declare a match, while most of the audience sees the mixed light as greenish. These are the deuteranomalous observers. Next, as more red is added the majority will say that a match has been achieved. Finally, as yet more red is added, the remaining, protanomalous, observers will declare a match at a point where everyone else is seeing the mixed light as definitely reddish.

Protanomaly (1% of males, 0.01% of females): Having a mutated form of the long-wavelength pigment, whose peak sensitivity is at a shorter wavelength than in the normal retina, protanomalous individuals are less sensitive to red light than normal. This means that they are less able to discriminate colors, and they do not see mixed lights as having the same colors as normal observers. They also suffer from a darkening of the red end of the spectrum. This causes reds to reduce in intensity to the point where they can be mistaken for black. Protanomaly is a fairly rare form of color blindness, making up about 1% of the male population. Both protanomaly and deuteranomaly are carried on the X chromosome.
Deuteranomaly (most common - 6% of males, 0.4% of females): Having a mutated form of the medium-wavelength pigment. The medium-wavelength pigment is shifted towards the red end of the spectrum resulting in a reduction in sensitivity to the green area of the spectrum. Unlike protanomaly the intensity of colors is unchanged. This is the most common form of color blindness, making up about 6% of the male population. The deuteranomalous person is considered "green weak". For example, in the evening, dark green cars appear to be black to Deuteranomalous people. Similar to the protanomates, deuteranomates are poor at discriminating small differences in hues in the red, orange, yellow, green region of the spectrum. They make errors in the naming of hues in this region because the hues appear somewhat shifted towards red. One very important difference between deuteranomalous individuals and protanomalous individuals is deuteranomalous individuals do not have the loss of "brightness" problem.
Tritanomaly (equally rare for males and females): Having a mutated form of the short-wavelength (blue) pigment. The short-wavelength pigment is shifted towards the green area of the spectrum. This is the rarest form of anomalous trichromasy color blindness. Unlike the other anomalous trichromasy color deficiencies, the mutation for this color blindness is carried on chromosome 7. Therefore it is equally prevalent in both male & female populations. The OMIM gene code for this mutation is 304000 “Colorblindness, Partial Tritanomaly”.

Clinical forms of color blindness

Total color blindness
Achromatopsia is strictly defined as the inability to see color. Although the term may refer to acquired disorders such as color agnosia and cerebral achromatopsia, it typically refers to congenital color vision disorders (i.e. more frequently rod monochromacy and less frequently cone monochromacy).

In color agnosia and cerebral achromatopsia, a person cannot perceive colors even though the eyes are capable of distinguishing them. Some sources do not consider these to be true color blindness, because the failure is of perception, not of vision. They are forms of visual agnosia.

Red-green color blindness
Those with protanopia, deuteranopia, protanomaly, and deuteranomaly have difficulty with discriminating red and green hues.

Genetic red-green color blindness affects men much more often than women, because the genes for the red and green color receptors are located on the X chromosome, of which men have only one and women have two. Such a trait is called sex-linked. Females (46, XX) are red-green color blind only if both their X chromosomes are defective with a similar deficiency, whereas males (46, XY) are color blind if their single X chromosome is defective.

The gene for red-green color blindness is transmitted from a color blind male to all his daughters who are heterozygote carriers and are usually unaffected. In turn, a carrier woman has a fifty percent chance of passing on a mutated X chromosome region to each of her male offspring. The sons of an affected male will not inherit the trait from him, since they receive his Y chromosome and not his (defective) X chromosome. Should an affected male have children with a carrier or colorblind woman, their daughters may be colorblind by inheriting an affected X chromosome from each parent.

Because one X chromosome is inactivated at random in each cell during a woman's development, it is possible for her to have four different cone types, as when a carrier of protanomaly has a child with a deuteranomalic man. Denoting the normal vision alleles by P and D and the anomalous by p and d, the carrier is PD pD and the man is Pd. The daughter is either PD Pd or pD Pd. Suppose she is pD Pd. Each cell in her body expresses either her mother's chromosome pD or her father's Pd. Thus her red-green sensing will involve both the normal and the anomalous pigments for both colors. Such women are tetrachromats, since they require a mixture of four spectral lights to match an arbitrary light.

Blue-yellow color blindness
Those with tritanopia and tritanomaly have difficulty with discriminating blue and yellow hues.

Color blindness involving the inactivation of the short-wavelength sensitive cone system (whose absorption spectrum peaks in the bluish-violet) is called tritanopia or, loosely, blue-yellow color blindness. The tritanopes neutral point occurs at 570 nm; where green is perceived at shorter wavelengths and red at longer wavelengths. Mutation of the short-wavelength sensitive cones is called tritanomaly. Tritanopia is equally distributed among males and females. Jeremy H. Nathans (with the Howard Hughes Medical Institute) proved that the gene coding for the blue receptor lies on chromosome 7, which is shared equally by men and women. Therefore it is not sex-linked. This gene does not have any neighbor whose DNA sequence is similar. Blue color blindness is caused by a simple mutation in this gene (2006, Howard Hughes Medical Institute).

Epidemiology
Color blindness affects a significant number of people, although exact proportions vary among groups. In Australia, for example, it occurs in about 8 percent of males and only about 0.4 percent of females. Isolated communities with a restricted gene pool sometimes produce high proportions of color blindness, including the less usual types. Examples include rural Finland, Hungary, and some of the Scottish islands. In the United States, about 7 percent of the male population - or 21 million men - and 0.4 percent of the female population either cannot distinguish red from green, or see red and green differently (Howard Hughes Medical Institute, 2006). It has been found that more than 95 percent of all variations in human color vision involve the red and green receptors in male eyes. It is very rare for males or females to be "blind" to the blue end of the spectrum.

Prevalence of color blindness
Men Women Total References
Overall - - -
Overall (United States) - - 1.30%
Red-green (Overall) 7 to 10%
Red-green (Caucasians) 8%
Red-green (Asians) 5%
Red-green (Africans) 4%
Monochromacy
Rod monochromacy (no cones) 0.00001% 0.00001%
Dichromacy 2.4% 0.03%
Protanopia (L-cone absent) 1% to 1.3% 0.02%
Deuteranopia (M-cone absent) 1% to 1.2% 0.01%
Tritanopia (S-cone absent) 0.001% 0.03%
Anomalous Trichromacy 6.3% 0.37%
Protanomaly (L-cone defect) 1.3% 0.02%
Deuteranomaly (M-cone defect) 5.0% 0.35%
Tritanomaly (S-cone defect) 0.0001% 0.0001%

Diagnosis

Example of an Ishihara color test plate. The numeral "74" should be clearly visible to viewers with normal color vision. Viewers with dichromacy or anomalous trichromacy may read it as "21", and viewers with achromatopsia may see nothing.The Ishihara color test, which consists of a series of pictures of colored spots, is the test most often used to diagnose red-green color deficiencies. A figure (usually one or more Arabic digits) is embedded in the picture as a number of spots in a slightly different color, and can be seen with normal color vision, but not with a particular color defect. The full set of tests has a variety of figure/background color combinations, and enable diagnosis of which particular visual defect is present. The anomaloscope, described above, is also used in diagnosing anomalous trichromacy.

However, the Ishihara color test is criticized for containing only numerals and thus not being useful for young children, who have not yet learned to use numerals. It is often stated that it is important to identify these problems as soon as possible and explain them to the children to prevent possible problems and psychological traumas. For this reason, alternative color vision tests were developed using only symbols (square, circle, car).

Most clinical tests are designed to be fast, simple, and effective at identifying broad categories of color blindness. In academic studies of color blindness, on the other hand, there is more interest in developing flexible tests to collect thorough datasets, identify copunctal points, and measure just noticeable differences.

Treatment and management
There is generally no treatment to cure color deficiencies, however, certain types of tinted filters and contact lenses may help an individual to distinguish different colors better. Additionally, computer software has been developed to assist those with visual color difficulties.

Design implications of color blindness
Color codes present particular problems for color blind people as they are often difficult or impossible for color blind people to understand.

Good graphic design avoids using color coding or color contrasts alone to express information, as this not only helps color blind people, but also aids understanding by normally sighted people. The use of Cascading Style Sheets on the world wide web allows pages to be given an alternative color scheme for color-blind readers. This color scheme generator helps a graphic designer see color schemes as seen by eight types of color blindness. For an example of a map that could present a significant problem to a color blind reader, see this graphic from a recent New York Times article. The typical red-green color blind reader will find the green sections of the map nearly indistinguishable from the orange, rendering the graphic unreadable.

Designers should take into account that color-blindness is highly sensitive to differences in materiality. For example, a red-green colorblind person that is incapable of distinguishing colors on a map printed on paper may have no such difficulty when viewing the map on a computer screen or television. In addition, some color blind people find it easier to distinguish problem colors on artificial materials, such as plastic or in acrylic paints, than on natural materials, such as paper or wood.

When the need to process visual information as rapidly as possible arises, for example in a train or aircraft crash, the visual system may operate only in shades of grey, with the extra information load in adding color being dropped. This is an important possibility to consider when designing, for example, emergency brake handles or emergency phones.

Due to this inability to recognize colors such as red and green, some countries (e.g., Singapore prior to the 1990s or Romania (8% Discrimination) ) have refused to grant individuals with color blindness driving licenses.

Misconceptions and compensations
Color blindness is not the swapping of colors in the observer's eyes. Grass is never red, and stop signs are never green. The color impaired do not learn to call red "green" and vice versa. However, dichromats often confuse red and green items. For example, they may find it difficult to distinguish a Braeburn from a Granny Smith and in some cases, the red and green of a traffic light without other clues (e.g., shape or location). This is demonstrated in this simulation of the two types of apple as viewed by a trichromat or by a dichromat.

Color blindness almost never means complete monochromatism. In almost all cases, color blind people retain blue-yellow discrimination, and most color blind individuals are anomalous trichromats rather than complete dichromats. In practice this means that they often retain a limited discrimination along the red-green axis of color space although their ability to separate colors in this dimension is severely reduced.

It should also be noted that even though some people are unable to see some or maybe even any of the numbers in (e.g. red-green) color blindness test, the person might still be able to tell the difference between the colors in his or her everyday life.

Is Colour Blindness Dominant or Recessive Desease

Acardi Syndrome

Aicardi syndrome is an uncommon malformation syndrome characterized by absence of a key structure in the brain called the corpus callosum, the presence of retinal abnormalities, and seizures in the form of infantile spasms. Aicardi syndrome is inherited as an X-linked dominant trait that is lethal in males.

History
This disorder was first recognized as a distinct syndrome in 1965 by Jean Aicardi and Françoise Goutières, both French neurologists. Because both of these neurologists played a role in describing this disorder, it is sometimes called the Aicardi-Goutières syndrome.[1]

Epidemiology
Around 500 cases of Aicardi syndrome have been reported worldwide. Except that the syndrome is fairly uncommon, its precise frequency in the population is unknown.

Genetics
Almost all reported cases of Aicardi syndrome have been in females. The few males that have been identified with Aicardi syndrome have proved to have 47 chromosomes including an XXY sex chromosome complement, a condition called Klinefelter syndrome.

Aicardi syndrome appears to be lethal in normal males who have only one X chromosome (and a Y chromosome). In other words, Aicardi syndrome appears to be inherited in an X-linked dominant pattern due to a mutant gene on the X chromosome that is lethal in XY males.

All cases of Aicardi syndrome are thought to be due to new mutations. No person with Aicardi syndrome is known to have transmited the X-linked gene responsible for the syndrome to the next generation.

Features
Children are most commonly identified with Aicardi syndrome between the ages of three and five months. A significant number of these girls are products of normal births and seem to be developing normally until around the age of three months, when they begin to have infantile spasms. The onset of infantile spasms at this age is due to closure of the final neural synapses in the brain, a stage of normal brain development.

Diagnosis
Aicardi syndrome is characterized by the following triad of features:

Partial or complete absence of the corpus callosum in the brain (agenesis of the corpus callosum);
Eye abnormalities known as "lacunae" of the retina that are quite specific to this disorder; and
The development in infancy of seizures that are called infantile spasms.
Other types of defects of the brain such as microcephaly, porencephalic cysts and enlarged cerebral ventricles due to hydrocephalus are also more common in Aicardi syndrome.

Treatment
Treatment of Aicardi syndrome primarily involves management of seizures and early/continuing intervention programs for developmental delays.

Additional complications sometimes seen with Aicardi syndrome include porencephalic cysts and hydrocephalus, and gastro-intestinal problems. Treatment for prencephalic cysts and/or hydrocephalus is often via a shunt or endoscopic fenestration of the cysts, though some require no treatment. Placement of a feeding tube, fundoplication, and surgeries to correct hernias or other gastrointestinal structural problems are sometimes used to treat gastro-intestinal issues.

Prognosis
The prognosis (outlook) varies widely from case to case. However, all individuals reported with Aicardi syndrome to date have experienced developmental delay of a significant degree, typically resulting in moderate to profound mental retardation. The age range of the individuals reported with Aicardi syndrome is from birth to the mid 40’s.

Acardi Syndrome